<style>
    .form-wrapper {
        width: 300px;
        background-color: #ccc;
        padding: 20px;
        margin: 0 auto;
    }
    
    .form-wrapper>h2 {
        margin-bottom: 10px;
        text-align: center;
    }
    
    .form-wrapper section {
        margin-bottom: 10px;
    }
    
    .form-wrapper label {
        display: block;
    }
    
    .form-wrapper>form span {
        width: 100px;
        text-align: center;
        display: inline-block;
        text-align: right;
    }
    
    .submit-button {
        text-align: right;
    }
</style>

<div class="form-wrapper">
    <h2>sing in</h2>
    <form action="/ajax/register" method="POST">
        <section>
            <label>
           <span>
           name:
           </span> 
            <input type="text" id="name" name="name">
       </label>
        </section>
        <section>
            <label for="age">
               <span>
               age:
               </span> 
                    <input type="text" id="age" name="age">
            </label>
        </section>
        <section>
            <label>
           <span>
             password:
           </span> 
            <input type="password" id="password" name="password">
       </label>
        </section>
        <section class="submit-button">
            <input type="submit" value="submit">
        </section>
    </form>
</div>